Radiation therapy is a principle treatment modality for many cancers and other diseases. In the last 15 years, the sophistication, precision, and capabilities of these treatments has increased dramatically. Examples include intensity-modulated-radiation-therapy (IMRT), volumetric-modulated-radiation-therapy (VMAT), MRI guided radiation therapy (e.g., Viewray), stereotactic-body-radiation therapy (SBRT), and many others. These techniques have extraordinary capability to deliver complex three dimensional (3D) distributions of dose that conform to even irregularly shaped lesions in the patient. The increased complexity or delivery technology has led to a need for new verification methods and technologies in order to strengthen the foundations of quality assurance (QA) in radiation therapy (RT). Such end-to-end verification has long been a critical final step performed during commissioning of new RT techniques and devices, prior to their implementation in the clinic.
Historically, end-to-end verification and commissioning of advanced RT techniques has been performed by labor intensive procedures with poor spatial resolution (e.g., using film phantoms). More comprehensive 3D dosimetry techniques have been developed, with notable examples being PRESAGE® (Heuris, Inc., Skillman, N.J.), Fricke gels, and BANG gels (MGS Research, Inc., Madison, Conn.). However, their implementation in clinical practice has been heavily slowed by many factors, including expense, volatility, the need for extensive training and expertise, and inflexible phantom geometries. PRESAGE® dosimeters, in particular, are able to address most of these issues, but expensive optical scanning tools are necessary for dose readout. One example of such a costly system is the Duke Large field of view Optical Scanner (DLOS) system developed at Duke (Thomas et al. 2011). In the DLOS system, the telecentric lenses and fluid tank (and fluid accessories) contribute to over 60% of the total cost.
To improve accessibility of comprehensive 3D dosimetry techniques, there is a desire for a low-cost, reliable, and easy-to-use 3D dosimetry system.